Significant changes in the Oregon Health Plan (OHP) have created a unique opportunity to investigate impacts on patients enrolled in methadone maintenance services when the Oregon State Legislature eliminated payment for methadone maintenance and outpatient chemical dependency services for those under the Medicaid expansion, Oregon Health Plan-Standard. Approximately 5,000 clients in Oregon were enrolled in methadone services and 3,000 were receiving OHP Standard prior to these cuts. Thus, beginning March 1, 2003, 3,000 patients were required to self-pay in order to continue receiving methadone services. This study is currently following 151 methadone clients recruited in February and March 2003 and randomly selected to participate in this project. The sample selection was a randomized quasi-experimental study of three groups of clients, (a) those who lost their benefits and were removed from methadone involuntarily, (b) those who attempted to pay out of pocket for methadone, (both received benefits under the OHP Standard) and (c) those who retained their benefits through Medicaid (OHP-Plus). The first wave of data collection began in February 2003; with a second wave in the first weeks of April 2003; and a third data collection point is scheduled for June 2003. Interviews with the Addiction Severity Index, Treatment Services Review and Health Risk Behavior Survey and a chart review of clinical data constitute the first three waves of data collection. This application seeks funding for a one-year follow up interview (Wave 4) as a continuation of earlier work funded by the Robert Wood Johnson Foundation and the Oregon Practice Improvement Collaborative. Data from clients' clinical records one year following the beginning of the study and abstraction of data from four Oregon administrative databases that monitor legal, employment, addiction services and Medicaid reimbursements will round out the data collection for this project. All four completed interviews will provide time series data on the Addiction Severity Index scales (drug use, alcohol use, legal problems, medical problems, family problems, employment problems, and psychiatric problems), participation in mental health, addiction treatment and health care services (Treatment Services Review), and HIV risk behaviors (Risk Behavior Survey). The analysis for these data will present characteristics of methadone clients with respect to differences between the three groups. Means, standard deviations and ranges of the ASI composite scores will be presented examining the levels of addiction behaviors that characterize the sample. Demographic variables including age, gender, length of addiction, dosing levels will also be presented at all four waves. Also, a description of how many OHP-Standard patients were able to successfully self-pay for their methadone treatment on their own will be presented. The main part of the analysis will consist of structural equation models that will be used to isolate slopes and intercepts for addiction behaviors over time, examining any differences between the three client groups and the mediators and moderators of these growth curves.